1. Field of the Invention
The present invention generally relates to a system for creating a tuning voltage for a receiver.
2. Description of Related Art
Typically, electronic receivers require tuning voltages to be provided to radio frequency (RF) tuning filters that track the tuning frequencies of an input signal. However, most radio microprocessors do not have a programmable tuning voltage generator. To create tuning voltages, many radios use complex circuits in addition to the microprocessor. For example, one common implementation utilizes two operational amplifiers, four transistors, and a number of resistors in communication with four control lines of the radio microprocessor. This implementation creates a voltage divider circuit to generate the tuning voltage for frequency tracking. Even if complex circuits are used, many times poor frequency tracking results, thereby compromising receiver performance.
In view of the above, it is apparent that there exists a need for an improved system for creating a tuning voltage.